QToolBar positioning within QMainWindow

I have a standard QMainWindow application into which I dock both vertical and horizontal toolbars. However I don't seem to be able to dock them such that the vertical bars occupy the corners in preference to the horizontal ones. Since this is a widescreen application and needs to work with touch screens as well, the vertical bars on the sides are the main control bars and the horizontal ones are secondary, hence the requirement.

Is this possible? If not how would I request a change to make it possible?